/Engine/Source/Runtime/MovieScene/Public/Evaluation/PreAnimatedState/MovieScenePreAnimatedStateExtension.h
The templated type must implement a static GroupManagerID member of type TPreAnimatedStorageIDA pointer to the group manager, or nullptr if it does not exist.
template<typename GroupManagerType> [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< GroupManagerType > FindGroupManager() const